1. Field of the Invention
This invention pertains to waterproof structures for waterproofing computer keyboard switches and protecting them from the surrounding environment. In particular, this invention relates to a waterproof structure which includes an upper protective cap having an arcuate face portion insertable within a key and surrounding a computer key post in watertight relation. Further, this invention pertains to a deformable portion of a protective cap to bear on an inner surface of a key member to increase the restorative forces after the computer key is pressed.
2. Prior Art
Referring to the structure of prior art computer key switches, such may be divided into four basic types. The first type is a mechanical system which is actuated by a generally metallic elastic member. The second type is capacitive in nature which can generate an on/off decision by changing the electrical capacity of a contact diode. The third type is a thin-film system which uses photographic technology to spread silverized glue on a halftone to generate a conductive circuit. The fourth type is a rubber system which is coated with a layer of carbonized conductor material with the rubber key connected to a printed circuit board. The characteristic of the above four computer key switch types are described as follows: The mechanical type applies the electric conductivity of metal to conduct which has an advantageous touching feel for the user. The capacitive type has a lower manufacturing cost, however, its quality is unstable. As to the rubber type, its size can be controlled easily, however, its use causes a serious pollution problem. The above four types all have a common fault, in that they fail to provide an effective waterproof structure for an associated keyboard switch. Thus, the design of the waterproof structure of a computer key switch is of major importance. At present, there are some kinds of computer key switches with waterproofing structures, however, they still have two major faults: (1) they only have a short-term and partial waterproof capability; and, (2) computer keys are enclosed with thick rubber plates which affect the appearance of the computer keys and causes inconvenient operation resulting in increased manufacturing costs.